DPT-RP1 Rooting Methods(Advice)

I have a Sony "DPT-RP1 digital paper" device. But it doesn't provide enough settings in order to navigate books easily.

Device is embedded with Android 5.1(Linux). Connection to the device is created using NDIS USB Networking. When you transfer PDF document to the device, It just encrypt package and send to IPv6 address of the device.

Digital Paper App is created using Electronjs framework. Janten created a python library which do all sort of task of the App.
check: https://github.com/janten/dpt-rp1-py

I think it may be possible to send files non-pdf files. The App doesn't allow it; because it check file extension at client side. But this python library may send any file such as ".sh".

Also, there are some input forms which we can buffer overflow. You can set device name, search a file name.

If we utilize these methods, will they be useful for rooting?